The loss of objects of common use is a daily problem in houses, care homes, etc. . . . If we add to this that one or all persons living in that house have a partial or total visual impairment, the problem is magnified. Moreover, some objects can be of non-easy localization in scenarios other than the domestic, like in emergency situation scenarios or in retailing when the presence of many objects and users not specially prepared to locate a specific item must be guided to find them out in a very efficient way. Based on the above, often, is necessary to locate objects in a controlled environment, where it is known with certainty that the object is in the surroundings but not with total accuracy or, oppositely, to assure that the search object is not present. Therefore, the ability to locate objects is limited by the distribution, size and mobility of the furniture, as well as the availability of devices easily attachable to any object regardless of its size.
Among the related publications of the state of the art, document US 20070013541 must be mentioned, which discloses an inventory system applied in a laboratory. Each object to be inventoried bears a RFID tag that is registered by readers fixed in the cupboards, storing the information in a database.
Document US 20090167495 describes a method for adapting RFID tags for its use in the localization and status indication of objects placed on shelves.
The system described in document WO 2010056287 provides one possible solution to the monitoring of patient samples in a hospital using RFID technology. RFID transponders attached to the samples store data associated with the patient from whom they were taken.
The system of document US 20050270158 discloses a possible solution for those cases in which the aim is to track both people and moving objects that pass through specific and fixed areas.
The US 20060190538 proposal consists in labeling the different devices of a house with RFID tags that allow knowing their location in a dynamic manner. This information is gathered in a central server where there is a record of the locations in real time.
The US 20060208925 system is based on transmitting information on the position received by means of a GPS system. The transmission of said information is carried out via a RFID link to the nearby locations.
WO 2006045819 describes a beaconing system using RFID tags on sidewalks that store spatial information already known due to the existence of a database.
The system described in WO 2005071597 also uses beaconing through RFID tags, but making a mesh on the ground. These tags can also store information about nearby objects or of special interest.
Document WO 2007072389 describes an indoor guiding method where RFID tags are also used as beacons that store spatial information about nearby objects.
Document ES 2324085B1 describes an object locating and tracking system where the RFID reader is integrated into a phone or mobile device carried by the user. As it moves through the area, it gathers information from nearby objects, which is stored in a database. Therefore, to detect an object it is necessary that the user has moved around its immediate surroundings in the past and the database may become obsolete if someone else changes the location of an object.
An outdoor navigation system for the visually impaired is described in document WO 2006065430, wherein thanks to sensors carried by the person in the walking cane and ankles the person is guided. Path mapping is carried out through GPS technology, and the system further integrates information received from the Internet.
A similar system is described in US 20050140544, where the tracking is carried out using GPS information and information received from the Internet wirelessly.
Document WO 2004059598 describes a method of audio description whereby a person carrying an RFID reader in their hand reads information from nearby tags, which is acoustically transferred to the user.
Document KR20100068850-A discloses a device and a method for locating an object to which an RFID tag has been added, using a portable terminal with an RFID reader, which interrogates the RFID tag and performs measurements of the strength of the response radio-frequency signal of the RFID tag, calculating based on said strength, the distance from the portable terminal to the object and displaying the result on a screen. However, unlike the present invention, the invention disclosed in said document does not allow an accurate and fast location, since the user does not know from where to start looking for the object, so that if the area is very large, the user may need to explore all the rooms of the area until detecting the response from the RFID tag (the response range of RFID tags is very small).
The problem posed by the art, therefore, is to achieve a system for the spatial location of objects allowing a fast and accurate Telecare services for people with or without partial or total visual disabilities in a more efficient way, in order to offer a better quality of life and independence at home.